Does VSync reduce fps?

Answered by Antonio Sutton

VSync, or vertical synchronization, is a feature in computer graphics that aims to synchronize the frame rate of a game with the refresh rate of the monitor. The purpose of VSync is to prevent screen tearing, a phenomenon where the monitor displays parts of multiple frames at the same time, resulting in a fragmented and visually unpleasant image.

One common misconception is that enabling VSync will reduce the frame rate of a game. While it is true that VSync can limit the frame rate to the monitor’s refresh rate, it does not inherently reduce the overall performance or fps (frames per second) of the game. Instead, it helps to create a smoother and more visually pleasing experience by eliminating screen tearing.

When VSync is enabled, the game’s frame rate is capped at the refresh rate of the monitor. For example, if you have a 60Hz monitor, VSync will attempt to lock the game’s frame rate at 60 fps. This means that the GPU (graphics processing unit) will wait for the monitor to finish refreshing before displaying the next frame, thus preventing screen tearing.

However, there can be drawbacks to enabling VSync. One of the most noticeable issues is input lag, which refers to the delay between when you perform an action and when it is displayed on the screen. With VSync enabled, the GPU may need to wait for the monitor’s refresh cycle to complete before displaying a new frame, resulting in a slight delay in the input response.

In situations where the game’s frame rate consistently exceeds the monitor’s refresh rate, enabling VSync may not be necessary, as screen tearing is less likely to occur. In fact, in such cases, leaving VSync disabled can potentially lead to higher frame rates, maximizing the performance of your system.

There are also variations of VSync called Adaptive VSync or Adaptive Sync, such as AMD’s FreeSync and NVIDIA’s G-Sync. These technologies dynamically adjust the monitor’s refresh rate to match the game’s frame rate, eliminating the need for traditional VSync. This can provide the benefits of VSync without the associated input lag, as the refresh rate adapts to the game’s performance.

In my personal experience, enabling VSync has been beneficial in games where screen tearing was noticeable, especially in fast-paced action games or games with rapid camera movements. However, I have also encountered situations where VSync caused noticeable input lag or where the game’s frame rate dropped significantly due to the hardware struggling to maintain a steady 60 fps.

VSync does not inherently reduce the fps of a game but rather locks it to the monitor’s refresh rate to prevent screen tearing. Whether to enable VSync or not depends on individual preferences and the specific game being played. It is worth experimenting with VSync settings and considering alternatives like Adaptive VSync or Adaptive Sync technologies to find the best balance between visual quality, performance, and input responsiveness for your particular setup.